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SUMMARY:Quantum Critical Scaling of the Geometric Tensors - Gen Zhang (Uni
 versity of Cambridge)
DTSTART:20101105T153000Z
DTEND:20101105T160000Z
UID:TALK27259@talks.cam.ac.uk
CONTACT:Daniel Cole
DESCRIPTION:"L. C. Venuti and P. Zanardi\, PRL\, 99\, 095701 (2007) ":http
 ://prl.aps.org/abstract/PRL/v99/i9/e095701\n\nBerry phases and the quantum
 -information theoretic notion of fidelity have been recently used to analy
 ze quantum phase transitions from a geometrical perspective. In this Lette
 r we unify these two approaches showing that the underlying mechanism is t
 he critical singular behavior of a complex tensor over the Hamiltonian par
 ameter space. This is achieved by performing a scaling analysis of this qu
 antum geometric tensor in the vicinity of the critical points. In this way
  most of the previous results are understood on general grounds and new on
 es are found. We show that criticality is not a sufficient condition to en
 sure superextensive divergence of the geometric tensor\, and state the con
 ditions under which this is possible. The validity of this analysis is fur
 ther checked by exact diagonalization of the spin-1/2 XXZ Heisenberg chain
 .
LOCATION:TCM Seminar Room\, Cavendish Laboratory
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